Simulation of Differential Ion Mobility (DMS) Principle Coupled with Mass Spectrometry in Atmospheric Pressure
F. Sinatra, T. Wu, A. Avila, E. Nazarov, T. Evans-Nguyen, J. Wang
Draper Laboratory, Tampa, FL, USA
University of South Florida, Tampa, FL, USA
Mass spectrometry is an analytical technique widely used in the scientific community to determine chemical composition of sample compounds. Typically, mass spectrometers perform their analysis under vacuum conditions, though atmospheric pressure mass spectrometers are becoming more prevalent. With the development of atmospheric pressure mass spectrometers, techniques such as FAIMS (Field ...
Modeling the Effect of Discrete Distributions of Platinum Particles in the PEM Fuel Cell Catalyst Layer
C.F. Cetinbas, A.K. Prasad, S.G. Advani
Center for Fuel Cell Research, Department of Mechanical Engineering, University of Delaware, Newark, DE, USA
University of Delaware, Newark, DE, USA
In this study, the basic catalyst layer (CL) structure, consisting of carbon-supported Pt particles (C|Pt) and an ionomer binder, is investigated numerically by using COMSOL. The significance of modeling discrete Pt particles on the carbon support is highlighted by comparing the cell performance results to the case in which the Pt is assumed to be distributed uniformly over the carbon support as ...
A. Fayolas , M.G. Sanku, M. Pascoa, M. Xynou
KTH Royal Institute of Technology, Stockholm, Sweden
The objective of the study is to investigate the chiral separation of Tröger’s base enantiomers using batch chromatography. Because of its resolution, chromatography is often the preferred method for chiral separations. The separation of Tröger’s base is resolved by using the COMSOL Multiphysics® software. It is modeled by one dimension geometry, having the length of the column set and computed ...
Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
Debris, micro particles produced by discharges, stay in the gap area during deep hole machining by micro EDM, cause short-circuits and abnormal discharges, finally make machining impossible. Although a deep hole can be processed by using the tool with grooves on the surface, the effect of the tool shape on the flow of working fluid and the behavior of debris are not clear yet. In this research, ...
Thermal Natural Convection Simulations with COMSOL Multiphysics® in Comparison with Measurements - new
H. van Halewijn
Fontys University of Applied Physics, Eindhoven, The Netherlands
In a laboratory setup a horizontal rod is heated on one side. By natural convection a stable temperature pattern is developed. Using the Nusselt formulation of the natural convection of cylindrical rods, the temperature distribution can be calculated. Only a good match of the simulations and the measurements can be reached when taking into account all the non-linear physics in the system. In ...
J. M. Meot , A. Briffaz , J. Jacquin , S. Rashidi 
 Cirad, UMR QualiSud, Montpellier, France
 Bureau national Interprofessionnel du Pruneau, Villeneuve, France
A 1D-axisymmetric model was built to represent the drying of a single d’Ente plum to d’Agen prune. Underlying assumptions of the model were those of Di Matteo et al. 2003. Sorption isotherms of plum come from Tsami et al, 1990 and equation structure of apparent water diffusion coefficients from Sabarez, 2001. External transfer coefficients were adjusted by direct measurements. The parameters of ...
H. van Halewijn ,
 Fontys University of Applied Physics, The Netherlands
At the Fontys University of Applied Physics (The Netherlands) a plasma etcher has been acquired for educational purposes. The machine operates at low power up to 30 Watt and is driven with a magnetic coil at 13.56 MHz. The use of COMSOL Multiphysics software will be discussed to simulate the temperature and mass fractions of the activated and ionized atoms in the gas. The simulations will be ...
ABB, Ladenburg, Germany
Medium- and high-voltage circuit breakers and reclosers are important grid protection devices that connect different grid sources and increase the network/grid reliability. Currently, there is a clear need of increasing the numbers of switching operation. Therefore, the optimal design of these devices becomes of extreme importance in order to enable the required switching capabilities. This ...
H. Weng , Y. Yang , B. Liu , X. Ma 
 Institute of Semiconductors, Chinese Academy of Science, Beijing, China
In the past decades, equilateral polygonal microcavity lasers with whispering-gallery modes (WGMs) have attracted great attentions due to their potential application in photonic-integrated circuits. Compared to the perfect microdisk without deformation, the polygonal microcavities such as triangle, square, hexagonal and octagonal can easily realize the light directional emission and single mode ...
李晓南 , 刘国强 ,
利用惯性力学和电磁学，研究了一个金属小车沿着磁铁铺就的轨道做减速直线运动。其中，小车也可以看成是携带等量的磁铁剩磁，且沿着铁磁轨道减速运动。通过赋予小车一个初速度，例如100 m/s，然后再根据实际情况、赋予它一个特征密度，即小车有了一定的质量。当认为小车沿水平方向的轨道减速运动，忽略重力、空气阻力等其他一些影响因素时，小车将只受电磁的洛伦兹力的作用，而逐渐减速到零。 利用最新版的 COMSOL Multiphysics®，建模过程中，主要用到了“磁场和电场(mef)”和“全局常微分和微分代数方程(ge)”接口，涉及到的动力学和电磁学方程为 dv/dt=F/m F ⃗=∫_(V_vehicle)▒〖(J_induced ) ⃗×B ⃗dv〗 J_(i_y)=σ(v_z∙B_x-v_x∙B_z ) v 为小车即时速度，F 为洛伦兹力，J 为感应产生的涡流，v 为速度，B ...